Traumatic cervical spinal cord injury: relationship of MRI findings to initial neurological impairment.

PURPOSE

To quantify the degree of available space for the cord and cord swelling in patients following traumatic cervical spinal cord injury (TCSCI), and to assess the relationship among the available space for the cord, cord swelling, and the severity of neurological impairment.

METHODS

This study included 91 patients. The following indexes were measured by two blinded observers: maximum cord available area (CAA) and maximum cord swelling area (CSA). The American Spinal Injury Association (ASIA) impairment scale (AIS) grades were used to evaluate the extent of neurological injury. Relationship among CAA, CSA, and initial AIS grades was assessed via univariate and multivariate analyses.

RESULTS

Patients who were AIS grade A (complete injury) demonstrated significantly greater median CAA and CSA than AIS grade C or D (incomplete injury) (P < 0.01). Multivariate analysis identified only CAA (OR 20.88 [95% CI 1.50-291.21]; P = 0.024) and CSA (OR 17.84 [95% CI 1.15-276.56]; P = 0.039) were identified as independently influencing the likelihood of complete injury at the initial assessment. The classification accuracy was best for CAA and CSA; areas under the curve were 0.8998 (95% CI 0.7881-1.0000) and 0.9167 (95% CI 0.8293-1.0000), respectively.

CONCLUSION

The present study provides a novel radiologic method for identifying the severity of TCSCI with T2-weighted MRI findings. Greater available space for the cord (CAA > 38%) and cord swelling (CSA > 29%) can be used to identify patients at risk for TCSCI and both imaging characteristics are associated with an increased likelihood of severe neurological deficits.

LEVEL OF EVIDENCE

Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.